Hardware Transcoding stopped working

numetaler

Hello everyone, for some time now, I have been experiencing issues with hardware transcoding. I am uncertain if this is the appropriate forum, as I am using linuxserver.io docker.

I am utilizing a Synology DS918+ as my hardware.

/dev/dri is passed to the container and something is being done, but regardless of whether I use h265 or h264, the image on my end devices remains black or freezes immediately. Among other things, I use an Android phone with the TVHClient app, an Android TV with Kodi, and a Raspberry Pi 5. Each of the devices exhibits the same behavior.

When streaming is active, I can see on the status page in the tvheadend web interface that the server is working and transcoding and transmitting. I can also see on my phone that the current Wi-Fi usage is increasing.

Since I haven't changed my settings, I think something has changed in tvheadend.

Can anyone tell me if I need to change my settings now, and if so, what exactly?

Best regards!!

btw my settings for transcoding:

numetaler

here is a screenshot of the log when starting a stream with TVHClient wich is then playing in VLC on my phone

ukn_unknown

for some time now, I have been experiencing issues with hardware transcoding.

Can you estimate the actual time? 1 month, 3, 6, 1 year?

I am utilizing a Synology DS918+ as my hardware.

In order to understand what is going on we need:
what CPU do you have? Celeron J3455?
what OS you use?
what tvh version you have? was compiled by you?
can you copy the text from right side of build number after you click 'Toggle details'?

/dev/dri is passed to the container and something is being done, but regardless of whether I use h265 or h264, the image on my end devices remains black or freezes immediately. Among other things, I use an Android phone with the TVHClient app, an Android TV with Kodi, and a Raspberry Pi 5. Each of the devices exhibits the same behavior.

Try to change the Container to MPEG-TS/av-lib.
Also change default values provided for: Rate Control (CQP, CBR or VBR), Bitrate OR Constant QP.

numetaler

Hello, thanks for your reply and suggestions.

Can you estimate the actual time? 1 month, 3, 6, 1

I think its been between 1 and 3 month. and last sunday i switched from h265 to h264 wich was the last option wich was working. but im not 100% sure about this (if h264 was working). could be that my device picked pass as a profile. and after that i updated the docker container to be on latest again

what CPU do you have? Celeron J3455?

you are right with the cpu. so it should be apollolake

what OS you use?

Synology DSM 7.2.1-69057 Update 6 and TVH is running in linuxserver.io Docker. i keep it updatet to latest. i did not build TVH by myself or use the Community package from Synocommunity
Current Version is : HTS Tvheadend 4.3-2434_gb3974f7d6 (2025-08-09T15:47:55+0000)

Try to change the Container to MPEG-TS/av-lib.
Also change default values provided for: Rate Control (CQP, CBR or VBR), Bitrate OR Constant QP.

I already did that and it did not help...

Feel free to give me some hints an tips how i can provide you infos / logs or test something for you.

best regards

ukn_unknown

numetaler

I think its been between 1 and 3 month.

About one month a go we changed some fundamental things in transcoding. Like you said ... might be a coincidence.
The good news is that old code is still in source code ... all you have to do is change one line of code (I can tell you what) and you should be able to compile with old implementation.
The bad news is that you need to compile from source code 🙁 .
Before discussing about changes you should try to compile the Master from source code to confirm it works as expected.

Current Version is : HTS Tvheadend 4.3-2434gb3974f7d6 (2025-08-09T15:47:55+0000)

This is up to date.
Do you have the ability to install older version of tvh? If you have this option I can look what version (somewhere about 2400) was the version where we changed the transcoding in order for you to install something before that number and test transcoding.
Frankly I not an expert in docker ... I use tvh 'bare metal' on a lubuntu OS. I can recommend you some documentation like: https://docs.tvheadend.org/documentation/development/compiling/compiling-tvh-with-vaapi-support/for-lubuntu-24.04 . There are also some info about installing with docker: https://docs.tvheadend.org/documentation/installation/docker
I will try to help but frankly compiling from source code is the first step.

numetaler

I can try to get an older container to test, but im sure it was working.
i don't think i could build it on my synology, so this isn't an option for me at the moment.
somewhere in the future i plan to move all of my server stuff to a small N100 or similar.

What kind of hardware can you recommend where transcoding is working?

Is it possible that in the future my setup works again? i mean are these fundamental changes completed or is it in development at the moment?
Normaly it should work with the docker container as well. i mean it has access to the hardware and it worked in previous versions...

numetaler

Sorry for double posting, but i couldn't edit my last reply...

can you tell me the the github commit that i can search for a container previous to that?

i think for now i setup 2 containers. One with latest TVH running and one where transcoding was working for my setup

numetaler

back again from testing.

i startet a container with this commit: 730718c. H265 and H264 transcoding work just fine here.

numetaler

testet with Build: 4.3-2430_gda9fa6032 and it worked just fine on this version

ukn_unknown

If this commit was working:

is good news ... because the big changes are before.
I was wrong on my estimation ... (time fly ... ): Commits on May 19, 2025 --> this is the major change.
The usual suspects:

make sure that container and user has access rights to access hw accelerator.
make sure tvh was compiled with the proper components selected (BTW: you didn't sent me:

can you copy the text from right side of build number from About page, after you click 'Toggle details'?

let's recap the changes that I think are affecting transcoding:

There is a setting: Hardware Acceleration Details --> can you check how many options you have available? that will tell me indirectly if vaapi was compiled.

Regarding a new HW ... we need to discuss more on what is your goal for transcoding. Why do you want to transcode ?How many concurrent transcoding streams? What resolution (IN and OUT) and frame rate? Are you picky on quality of the transcoding 🙂 (this makes a big difference)? Are you constrained in bandwidth ? how much bit rate can you achieve?

numetaler

sorry i got you wrong. thougt you just need the build number 🙂

BTW: you didn't sent me:

Configure arguments:
--disable-ffmpeg_static --disable-libfdkaac_static --disable-libtheora_static --disable-libopus_static --disable-libvorbis_static --disable-libvpx_static --disable-libx264_static --disable-libx265_static --disable-libfdkaac --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --disable-avahi --disable-dbus_1 --disable-bintray_cache --disable-execinfo --disable-hdhomerun_static --enable-hdhomerun_client --enable-libav --enable-pngquant --enable-trace --enable-vaapi --infodir=/usr/share/info --localstatedir=/var --mandir=/usr/share/man --prefix=/usr --python=python3 --sysconfdir=/config

Compiler:
Using C compiler: cc
Using LD flags: -lhdhomerun -ldvbcsa
Build for arch: x86_64

Binaries:
Using PYTHON: python3
Using GZIP: gzip
Using BZIP2: bzip2

Options:
pie yes
ccdebug no
cardclient yes
cwc yes
cccam yes
capmt yes
constcw yes
linuxdvb yes
satip_server yes
satip_client yes
hdhomerun_client yes
hdhomerun_server yes
hdhomerun_static no
iptv yes
tsfile yes
dvbscan yes
timeshift yes
trace yes
avahi no
zlib yes
libav yes
ffmpeg_static no
libx264 yes
libx264_static no
libx265 yes
libx265_static no
libvpx yes
libvpx_static no
libtheora yes
libtheora_static no
libvorbis yes
libvorbis_static no
libfdkaac no
libfdkaac_static no
libopus yes
libopus_static no
nvenc no
vaapi yes
mmal no
omx no
inotify yes
epoll yes
pcre no
pcre2 yes
uriparser yes
ccache no
tvhcsa yes
bundle no
pngquant yes
kqueue no
dbus_1 no
android no
gtimer_check no
slow_memoryinfo no
libsystemd_daemon no
pcloud_cache yes
ddci yes
cclang_threadsan no
gperftools no
execinfo no
mmx yes
sse2 yes
W_unused_result yes
f_stack_protector yes
f_stack_protector_strong yes
f_stack_check yes
f_PIE yes
strlcat yes
strlcpy yes
fdatasync yes
getloadavg yes
atomic32 yes
atomic64 yes
atomic_time_t yes
atomic_ptr yes
bitops64 yes
qsort_r yes
time_ld yes
stime yes
gmtoff yes
recvmmsg yes
sendmmsg yes
gnu_libiconv yes
libiconv yes
ifnames yes
py_gzip yes
bin_pkg_config yes
bin_xgettext yes
bin_msgmerge yes
bin_gzip yes
bin_bzip2 yes
ssl yes
linuxdvbapi yes
linuxdvb_ca yes
libhdhomerun yes
upnp yes
hwaccels yes
inotify_h yes
inotify_init1 yes
dvbcsa yes
epoll_create1 yes
mpegts yes
mpegts_dvb yes

Packages:
openssl 3.3.4
zlib 1.3.1
libpcre2-8 10.43
liburiparser 0.9.8
libavfilter 7.110.100
libswresample 3.9.100
libswscale 5.9.100
libavformat 58.76.100
libavcodec 58.134.100
libavutil 56.70.100
libva 1.21.0
libva-drm 1.21.0

Installation paths:
Prefix: /usr
Binaries: ${prefix}/bin
Libraries: ${prefix}/lib
Data files: ${prefix}/share
Man pages: /usr/share/man

As i understand docker containers, someone builds them and changes the "app" inside the container, so that i just have to switch the container image and the whole "app" is updated. I have the container running with high priority what means it has root acces... (i know, shame on me)
so imho either the one who builds the app in the container (linuxservers.io) made some mistake or something in the new 3 commits is not compatible with my setup, i'm thinking.

The goal of the whole transcoding is that i sometimes work offshore and like to watch german tv in my spare time. bandwith is a problem in this case. so i always reduce resolution until i can watch somehow fluid.

the second goal is my father in law has some trouble with his own dish related to some strange interference. so he connects from time to time to my network via tailscale and can access my dish 🙂 in this cas im not to limited with bandwith. usually it works without transcoding, but i set his account to 720 wich works pretty much all the time

maximum streams i have is 2, but normal its just one

numetaler

forgot to mention: Resolution IN is up to 1080 what HD providers transmit and OUT is depending on my use case. either its 720 or i play with resolution and bitrate etc. until it works on that specific place. framerate isn't something i'd thougt of a lot, so it would normaly be 25 frames?

on the hardware acceleration details option i have auto (recommended) and prioritize vaapi. i tried both and both were not working

ukn_unknown

numetaler
tvh is compiled with vaapi and libav ... so it should work.

Now I have the big picture. I have some recommendation related to settings ... that should be discussed at some point.
Related to PC I don't think N100 is the best option ... in my opinion. Of course this is my personal opinion ... I will try to provide the information and you can decide for your self.
Let's start with some documentation:
https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video --> here is a good starting point to give you a big picture
Note: VAAPI is implemented using a subset of features from QSV (Intel Quick Sync Video).
Try to stick with ****lake that you see in that list ... all the others are refresh (low cost) versions.
Newer generations have better implementation and will generate better quality (for the same bitrate).
I recommend you to check the CPU (before buying) on https://www.cpu-monkey.com/en/ to see the GPU characteristics.
My personal observation was that CUs / Shader are a good indication of the quality of the video encoding (especially with QSV); higher is better.
If you search in Intel site: as example https://www.intel.com/content/www/us/en/products/sku/231803/intel-processor-n100-6m-cache-up-to-3-40-ghz/specifications.html you can look at GPU Specifications / Execution Units
Another important parameter that I found that correlate with quality is frequency range for iGPU: higher is better.

The lowest level of CPU I played with (I am going to skip raspberry pi 4) was https://www.intel.com/content/www/us/en/products/sku/93361/intel-atom-x5z8350-processor-2m-cache-up-to-1-92-ghz/specifications.html
Note: max GPU freq 500M and E.U. 12
The middle level is J4125 https://www.intel.com/content/www/us/en/products/sku/197305/intel-celeron-processor-j4125-4m-cache-up-to-2-70-ghz/specifications.html
Note: max GPU freq 750M and E.U. 12
J series is significantly better (has support for HEVC encoding).
The middle upper is Celeron 6305: https://www.intel.com/content/www/us/en/products/sku/208646/intel-celeron-6305-processor-4m-cache-1-80-ghz-with-ipu/specifications.html
Note: max GPU freq 1250M and E.U. 48
This option has a biffed up GPU ... CPU not so much. But if your target is HW encoding CPU is not required (AAC encoding is not a problem for any CPU this days). --> recommended for good quality/price
upper is i5-1240P: https://www.intel.com/content/www/us/en/products/sku/132221/intel-core-i51240p-processor-12m-cache-up-to-4-40-ghz/specifications.html
Note: max GPU freq 1300M and E.U. 80
This option is strong on GPU and CPU. Is at the boundary of being able to convert 2 stream 1080p -> 1080p H264 --> HEVC with B frame support in real time. I test it with QSV ... not VAAPI; but I am sure the comparison is close.

Now going to your actual CPU: https://www.intel.com/content/www/us/en/products/sku/95594/intel-celeron-processor-j3455-2m-cache-up-to-2-30-ghz/specifications.html
Note: max GPU freq 750M and E.U. 12
It is in the same category with other Jxxxx above; and I am tempted to say is in the same ballpark number with N100.
Note a small detail: N100 is alterlake-n (not alderlake): https://www.google.com/search?q=what+is+difference+from+alder+lake+and+alder+lake-N
I hope I didn't confuse you even more 🙂 ... let me know if you have any particular questions (or if you want my opinion on a particular CPU).

Now going back to your problem: Do you have the ability to test other containers in between? would help to narrow down ever further. Not being able to compile will hard for use to figure out what is the actual problem.
Can you copy the output of command vainfo -a in a text file and attached to your response?

numetaler

thank for your detailed detailed informations. i will work myself trough in the next time. thats a lot of work you put in there 👍️

i go on trying those containers one by one and tell you when the problem occurs

ukn_unknown

numetaler
Can you copy the output of command vainfo -a in a text file and attached to your response?

numetaler

if i connect with ssh to my synology the command gives me an error:

Trying display: drm
error: failed to initialize display

Makes sense, since there is no Display connected. i try to check inside the container

edit:
inside the container i cannot use this command

numetaler

i checked if my gpu is available in the container, and i looks like it is:

Alex@DiskStation:~$ sudo docker exec -it tvheadend_transcode ls -l /dev/dri
total 0
crw------- 1 root root 2445901728, 32552 Aug 14 05:46 card0
crw-rw---- 1 root videoe8bjvu11 2445901728, 32552 Aug 14 05:46 renderD128

numetaler

the next container i can test includes the commits b9d34f9 and 0af87f1 wich results in:
Build: 4.3-2432_g0af87f13f (2025-07-26T15:51:23+0000)

and here it stopped working... so it could be either one of those commits
VLC says the format i set (1280:720) but image is frozen from the start and i don't even have sound.

ukn_unknown

numetaler
To narrow down fully you need a container that includes the commits b9d34f9 --> frankly is hard for me to foreseen that changes from this commit might generate that behavior.
Can you remove (for testing only) the resize (instead of "Down (only)" select "Up & Down") ?

Trying display: drm
error: failed to initialize display

This is expected if you don't have monitor ... I need the rest of the text. Is strange that is trying to use 'drm' 🙁 . Should be something like ... Check if your versions of libva, vaapi and driver version are close to mine.

Trying display: wayland Trying display: x11 error: can't connect to X server! Trying display: drm libva info: VA-API version 1.18.0 libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so libva info: Found init function __vaDriverInit_1_18 libva info: va_openDriver() returns 0 vainfo: VA-API version: 1.18 (libva 2.18.0) vainfo: Driver version: Intel iHD driver for Intel(R) Gen Graphics - 23.2.1 () vainfo: Supported profile and entrypoints

numetaler

I think idon't get vainfo output because my synology is a nas without display connector. I think i can't get more information.

Regarding the docker i test one with the commit you said